The American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) Research Workshop (RW) has been a highly successful and a scientifically respected international conference; bringing together basic scientists, nutrition researchers and clinicians. The goal of the A.S.P.E.N. 2017 RW Gastric Bypass: Role of the Gut, is to focus on the exciting research evaluating gut-derived signals in modulating outcomes in Bariatric Surgery. Though gastric bypass surgery has undoubted positive effects, the mechanistic basis of the improvement cannot be solely explained by caloric restriction. Data suggest that bile acid metabolic pathways alter with bariatric surgery. New research also alludes to the role of gut microbiome changes leading to an improvement in outcomes. Given alteration of luminal nutrition with bariatric surgery, it is plausible that the resulting microbiome changes may play a role. Additionally, gut and hepatic nuclear factors and bile acid pathways, especially those involving the FXR, TGR5 and GLP axis, are modulated with bariatric surgery, which are additionally known to regulate gut microbiota. The A.S.P.E.N. 2017 RW is timely and novel and will provide a unique venue for inter-disciplinary collaboration among early career and established researchers from basic to applied science that are all seeking new solutions to the obesity problem. This RW is unique in that it is organized and brings together nutrition researchers from A.S.P.E.N. and from the fields of Gastroenterology, Hepatology, Immunology, Microbiology as well as Surgery facilitating interdisciplinary research collaborations, where they might not otherwise occur. This topic for the 2017 RW is of key relevance to A.S.P.E.N. researchers, and indeed for health care delivery, given the impact of obesity and improved outcomes from bariatric surgery. To advance the understanding there needs to be a topic focus, interdisciplinary collaborations and knowledge translation which is the precise aim of this RW. Thus, the aims of the 2017 A.S.P.E.N. RW program are: 1) to provide a venue for basic scientists and clinicians from a range of disciplines and across all levels of training and experience to focus on clinically relevant, and cutting-edge research on the mechanisms by which gut derived signals modulate outcomes post bariatric surgery, thus bridging basic research and clinical science; 2) to support translational science by fostering communication and collaboration among interdisciplinary researchers and clinicians thus bringing research from bench to bed-side; 3) to provide opportunities for mentorship of early career researchers / scientists and trainees; 4) to disseminate the 2017 RW activities and information to the broader scientific community. The 2017 RW is well placed to achieve these aims, having focused on a rapidly evolving scientific field that has broad relevance. Additionally, by establishing at the outset interdisciplinary collaborations; and given our proven success as evident in prior A.S.P.E.N. RW; the 2017 RW has a well-founded precedence of success in pertinent knowledge translation, thus advancing the science and patient care.